Locking devices for doors have been known for at least four thousand years, and probably originated in the Near East, where early forms of wooden locks operated by keys have been found in Egypt. Since this early period, the term lock has referred to a fastening device which included a bolt movable into a secure position by a key.
Eventually, because of improved technology, the term lock has become broader in meaning to encompass a fastening, as for a door, box, trunk lid, drawer, etc., in which a bolt is secured by any of various cooperating mechanisms and can be released by inserting and turning a key or by operating a special device, such as a combination, timing clock, automatic release button, magnetic solenoid, or other means.
Thus, a bolt may be best exemplified as a bar which is movable within a guide attached to a door to permit an end of the bar to fit into a fixed socket, or keeper, on an adjacent door jamb. Usually, a bolt is constructed so that the entire operating structure may be mounted on the surface of the door, lid, drawer, or other movable apparatus which requires securing or protection.
A typical bolt is intended to be controlled from just one side of a closure, as for example, the interior side of a house door. Too frequently, only a few small wood screws are provided for holding the bolt in place on a door where security is desired. Consequently, an intruder may simply force the door open easily without exerting a great deal of force, because the small wood screws are easily dislocated and because the door jamb is usually a weak structure.
The prior art describes numerous bolt and lock devices, such as those found in the following U.S. Pat. Nos.: 43,145, Warner, June 14, 1864, 188,134, Hill, Mar. 6, 1877, 257,141, Purves, Apr. 25, 1882, 284,519, Warren, Sept. 4, 1883, 291,352, Jewett, Jan. 1, 1884, 995,232, Edgar, Sr., June 13, 1911, 1,015,338, Peel, Jan. 23, 1912, 1,086,365, Hendren, Feb. 10, 1914, 1,159,877, Smith, Nov. 9, 1915, 1,364,757, Herrman, Jan. 4, 1921, 1,410,841, Simpson, Mar. 28, 1922, 1,520,509, Rancour, May 10, 1922, 1,617,813, Judge, Feb. 15, 1927, 3,264,018, Houvener, Aug. 2, 1966, 3,918,752, Leone et al, Nov. 11, 1975, 4,021,063, Porter, May 3, 1977, 4,341,408, Blevins, July 27, 1982.